The approaches described in this section are approaches that could be pursued, but not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated, it should not be assumed that any of the approaches described in this section qualify as prior art merely by virtue of their inclusion in this section.
Monochromatic liquid crystal displays (LCDs) such as those used for gasoline pump display digital clock displays are typically optimized for the middle of the visible light spectrum. Compared with green, which lies in the middle of the spectrum, red and blue light do not transmit well. Therefore, monochromatic LCDs may look greenish even when displaying black-and-white or grayscale images. In addition, monochromatic LCDs are unsuitable for display color images or video.
Color LCDs may be used to display black-and-white or grayscale images. Each pixel of the color LCDs comprises three or more color sub-pixels that can be used to simulate different shades of gray. However, when used as monochromatic displays, the resolution of color LCDs is typically limited by the area of the pixels which is three times larger or coarser than the area of each sub-pixel. Color artifacts may remain visible in certain spots, causing viewers to see a red or blue tinge around the edges of a supposedly black or grayscale character.
Since the light passing through the color filters of the color sub-pixels is attenuated, color LCDs may use backlights in addition to, or instead of, ambient light. As a result, power consumption of color LCDs, even when used as monochromatic displays, is high in order to achieve an acceptable resolution.
LCDs are typically refreshed at 30, 60, or 120 frames per second. At these frame rates, an LCD consumes much more power than at lower rates. For example, at a 60-frames-per-second rate, an LCD may consume twice the power than it would at a 30-frames-per-second rate.